1. Field of the Invention
The present invention relates to an image display device for illuminating an image display element, such as transparent-type liquid crystal, reflection-type liquid crystal, or DMD (micro mirror), by using light emitted from a light-source unit, and for enlarging and projecting an optical image formed on the image display element. Here, the light-source unit is configured by arranging a plurality of light sources such as LEDs which are semiconductor light-emitting elements.
2. Description of the Related Art
There has been known an image display device for illuminating an image display element, such as transparent-type liquid crystal, reflection-type liquid crystal, or DMD, by using light emitted from a light source, and for enlarging and projecting an optical image formed on the image display element.
As a trend in recent times, a study has been made concerning an image display device which employs, as the light source, the so-called LED elements such as light-emitting diodes which are semiconductor light-emitting elements or organic EL.
As a prior art, the following technology has been disclosed in JP-A-2003-280094: Namely, pitch of parallelizing elements of a parallelizing unit and pitch of element lenses of lens-array bodies in an integrator optical system are set such that both of the pitches will not coincide with each other. This setting allows uniformity of the illuminance on an illuminated body to be implemented with no coincidence established between centers of the parallelizing elements and optical axes of the element lenses.